#sqrt(1-sinx)=sqrt(sin^2(x/2)+cos^2(x/2)-2.sin(x/2)cos(x/2)##color(green)([As.sin^2theta+cos^2theta=1andsin2theta=2sinthetacostheta])#
#=sqrt((sin(x/2)-cos(x/2))^2##color(red)([As.a^2+b^2-2ab=(a-b)^2=(b-a)^2])#
#=sin(x/2)-cos(x/2)##color(brown)((Ans.))#